The myrosinase-binding protein from Brassica napus seeds possesses lectin activity and has a highly similar vegetatively expressed wound-inducible counterpart.
This communication demonstrates that proteins in the family of myrosinase-binding proteins (MBP) present in seeds of Brassica napus possess lectin activity, binding most efficiently to p-aminophenyl alpha-D-mannopyranoside-agarose, and to some extent to N-acetylglucosamine-agarose. A cDNA encoding a vegetatively expressed, wound-inducible counterpart to these seed MBP was isolated and characterised. Upon wounding, this MBP transcript accumulated in old and young leaves, and was systemically expressed in the young plant. Additionally, the wound-induced MBP transcript increased in abundance after treating the young plants with methyl jasmonate (MeJA), jasmonic acid (JA) or abscisic acid (ABA), and to some extent in response to the ethylene precursor 1-aminocyclopropane-1-carboxylic acid. Expression induced by wounding, ABA or JA was antagonised by simultaneous feeding of the plants with salicylic acid. MBP polypeptides accumulated in MeJA-treated plants. The myrosinases redistributed from the soluble fraction into the insoluble fraction of a tissue extract after induction. The most abundant MBP (94 kDa) partitioned in the insoluble fraction, while two larger MBP (103 kDa and 108 kDa) were present only in the soluble fraction of extracts obtained from the control or MeJA-treated plant tissues.
Taipalensuu
J
J
Uppsala Genetic Center, Department of Cell Research, Swedish University of Agricultural Sciences.
Eriksson
S
S
Rask
L
L
D000595:Amino Acid Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D015153:Blotting, Western; D001937:Brassica / Q000737:chemistry* / Q000201:enzymology; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D006023:Glycoproteins / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D006026:Glycoside Hydrolases / Q000032:analysis / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D037102:Lectins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000494:pharmacology; D037121:Plant Lectins; D010940:Plant Proteins / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D011485:Protein Binding; D012313:RNA / Q000032:analysis; D012639:Seeds / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D006023:Glycoproteins; D047908:Intracellular Signaling Peptides and Proteins; D037102:Lectins; C099049:MyAP protein, Brassica napus; D010937:Plant Growth Regulators; D037121:Plant Lectins; D010940:Plant Proteins; D012313:RNA; D006026:Glycoside Hydrolases; C022739:thioglucosidase